Locomotive



2 Sheets--Sheet 1' J. T. DAVIS.

LOCOMOTIVE.v

(No Model.)

Patented Oct. 4,1881.

2 Sheets-Sheet 2.

(No Model.)

J. T. DAVIS.

LOGOMOTIVE.

Patented Oct. 4,1881.

Jig

UNITED STATES PATE T OFFICE;

JOHN T. DAVIS, OF SAN FRANCISCO, CALIFORNIA.

LOCOMOTIVE.

SPECIFICATION forming part of Letters Patent No. 247,802. dated October 4, 1881,

Application filed February 4, 1881. (No model.)

To all whom it may concern Be it known that I, JOHN T. DAVIS, of the city and county of San Francisco, State of Gali- 'ments in that class of locomotives in which the driving-wheels act by rolling-friction upon corresponding friction-wheels secured to the same axle as the bearing-wheels, which run upon the track, and which have a smaller diameter than said bearing-wheels.

It consists in a means for increasing the frictional contact between the drivers and the driven wheels by means of hydraulic rams and in certain details of construction, more fully described hereinafter.

The object of my invention is to acquire increased speed with less power, whereby economy offuel and wear will result.

Referring to the accompanying drawings, Figure l is a view of my invention. Fig. 2 is a longitudinal section. Fig. 3 is a transverse section. Fig. 4 is a detail of construction.

LetArepresent a truck having the four bearing-wheels B, which are to'ruu upon the rails. The axles O of these wheels are made long enough to project through and extend upon the outside sufliciently to carry friction-wheels. These friction-wheels consist of two circular flanges or p1ates,the inner one of which is provided with an elongated hub, perforated to flt the projecting axle and extending outwardly, the other flange or plate fitting the axle and being pressed close to the end of the elongated hub of the inner one, thus forming a space or groove between the two plates or flanges. Within the groove thus made by the flanges of the friction -wheels paper is compressed by any suitable means to snfficient hardness to make a friction-surface around the wheels or hubs D, as shown in Fig. 4..

To secure the friction-wheels D to the wheels B, bolts to are driven through both flanges and the intervening paper of the saidfriction-wheels and through the wheelsB, being secured on the inside of the said wheels B.

When the compressed-paper surface becomes worn out of the circular, or otherwise unfit for use, it can be removed and other paper compressed around the friction-wheels, which will boot great conveuienceiu nothaving to change the wheels B. The friction-wheels are secured rigidly to the wheelsB, so that when they are turned by any power they also turn thewheels B. Let E represent the upper driving-wheels. The bearing-wheels B are separated sufficiently to allow the drivers E to drop between them so low that the axle F ofsaid drivers may pass beneath the boiler of the engine without unduly elevating it. These upper driving-wheels, E, rest upon the paper friction surface of the wheels D, and thus have four frictional points upon the said wheels.

' By holding the upper driving-wheels down upon the frictional wheels it will be seen that when the d rivin g-wheels are revolved they will revolve the wheels B, and by increasing the difference between the diameters of the drivers E and the diameters of the frictional wheels D the velocity of the locomotive is increased. Thus the speed of the lower wheels can be increased or diminished by increasing or diminishing the size of the drivers E or the size of the friction-wheels D.

In order to have the upper drivers, E, operate the supplementary or bearing wheels B, they must be held down upon the friction-wheels. For this purpose I have placed upon the frame of the truck A hydraulic rams- H, just under the axle F of the upper driving-wheels, and connected with said axle by a strap-joint, as shown, and with the frame of the truck. Prop,- er pump attachments connect the hydraulic rams with the water-tank, said rams being operated by a lever in the cab of the engine under the control of the engineer, so that in starting. the whole weight of the boiler may be thrown upon the upper drivers, increasing the friction. Thus the upper drivers, E, may be pressed down upon the friction-wheels D with whatever power is necessary for the required speed.

' An important feature in this construction is the placing of the drivers between the friction wheels D, because of the leverage obtained by this position of the drivers. When the power is applied to draw the axle of the drivers downward it produces, as a resultant, a pressure upon the separated friction-wheels, which is greater than the actual power applied in pro portion to the distance which these wheels are separated from each other and the length of the arc of the driving-wheels, which lies below the axle of the friction-wheels. This leverage upon these wheels tends to separate them, and must be resisted by a powerful truck-frame, A, which is properly trusscd and stayed to resist the strain. The journals of the axles O of the bearing-wheels may be surrounded by rollers, so as to form an anti-frictional journal-box, which will prevent undue friction of the journals when this leverage is applied. Another advantage of this position of the driver's be tween the wheels D is that all vertical movements of the bearing wheels B, caused by roughness of the track or for other reasons, are not transmitted to the drivers in a direct vertical line with their axle, and the effect upon these drivers is diminished in proportion to the amount in which the axle is out of the vertical line with the axles of the bearing-wheels. The rams H will also lift the drivers, when necessary, as on a downgrade, and permit the wheels B to travel without the aid of the friction. It is obvious that I may have one or two sets of upper drivers by having one or two trucks of bearing-wheels.

The boiler I, engine-frame, and cylinders .I may be supported entirely upon two or more sets of bearing and driving wheels, as herein described; or the rear end may be supported by a single set of these wheels, while the front may rest upon trucks of the ordinary construction. The pistons and piston-rods of the engine may be connected with the drivers E in the ordinary manner.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In alocomotive, and in combination with the drivers E, lying between and acting upon the friction-wheels D, so as to drive the wheels B by rolling contact, the hydraulic rams H, for drawing the axle F of the drivers toward the truck-frame of the bearing-wheels, whereby a greater power is produced to increase the frictional. contact between the drivers and the frictional wheels, substantially as described.

2. In combination with the truck A, having wheels B, said wheels having attached to their outsides the friction-wheels D, and the upper driving-wheels, E, resting upon the frictionwheels D, the hydraulic rams H, set upon the truck A and under the axle F of the wheels E, and connecting the two together, said rams H having pump-connections under the control of the engineer, whereby pressure is brought upon the upper driving-wheels,E,to force them down upon the friction-wheels D, substantially as described.

In witness whereof I have hereunto set my hand.

JNO. T. DAVIS.

Witnesses:

FRANK A. BROOKS, S. H. NoURsE. 

